<script>
var browser = {
  versions: function() {
    var u = navigator.userAgent;
    return {
            mobile: !!u.match(/AppleWebKit.*Mobile.*/), //是否为移动终端
            ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/), //ios
            android: u.indexOf('Android') > -1 || u.indexOf('Linux') > -1, //android
            iPhone: u.indexOf('iPhone') > -1 , //iPhone
            iPad: u.indexOf('iPad') > -1, //iPad
            webApp: u.indexOf('Safari') > -1 //Safari
        };
    }
}
if (browser.versions.mobile || browser.versions.ios || browser.versions.android || browser.versions.iPhone || browser.versions.iPad) {
    alert('移动端');
}else(
    alert('PC')
)

</script>